This is a Continuation of application Ser. No. 09/453,529 filed Dec. 3, 1999, now U.S. Pat. No. 6,678,247 the disclosure of which is incorporated herein by reference.
The present invention relates to a method for use in a telecommunication network by a data traffic policer, to a data traffic policer realizing such a method and to a telecommunication network including such a data traffic policer.
Such a method to police data traffic realized by such a data traffic policer is already known in the art e.g. from two contributions to the ‘ATM Forum Technical Committee’ and distributed to the ‘ATMF Traffic Management Working Group’. The first one, written by O. Bonaventure, P. Frêne and E. Desmet, with the aim to stimulate the formalization of the current textual conformance definition for the Guaranteed Frame Rate service category, was made available to the public on Feb. 8-13, 1998 at Anaheim, Calif., reference 98-0059. The second one, written by O. Bonaventure and E. Desmet, with the aim to discuss the possible options for a formal Guaranteed Frame Rate GFR conformance definition and propose of choice, was made available to the public on Apr. 20-24, 1998 at Berlin, Germany, reference 98-0281. These documents will be referred to by the reference numbers 98-0059 and 98-0281, respectively, in this application.
Both documents are describing conformance definitions for the Guaranteed Frame Rate service GFR category. Data traffic policing on a data communication link is performed for data traffic including data cells being grouped into frames. Upon reception of a data cell at such a data traffic policer, the data cell is checked upon its conformance by a decision means. The decision means provides a conformance result that is either conforming or non-conforming.
According to the 98-0281 document, each arriving data cell of a frame is verified upon its conformance by a conformance test e.g. a Peak Cell Rate test PCR, or Cell Delay Variation Tolerance test CDVT according to a Guaranteed Frame Rate GFR contract of a user. In the event that the head of a frame is conforming i.e. each data cell of the head of the frame is conforming, and a non-conforming data cell arrives, the following data cells of this frame i.e. the tail of the frame, except the last cell, is also declared as non-conforming.
It has to be explained that according to the management strategy of the operator a non-conforming cell is discarded or is marked as non-conforming. Marking a non-conforming data cell is called tagging. Furthermore, the tagged data cells and tagged frames are counted by the operator.
When the non-conforming cells are e.g. discarded, the conforming cells of the same frame which are already distributed into the network, becomes part of an incomplete frame which makes these conforming data cells also non-conforming. When the non-conforming data cells are e.g. marked, according to predefined statistic rules of the operator it is decided that at a predefined amount of non-conforming traffic, a connection is interrupted which makes again that conforming frames or conforming cells which are already distributed into the network are becoming non-conforming.
In this way, the conforming head of a frame that is distributed in the network becomes an incomplete frame and this incomplete frame utilizes network resources before being discarded at its destination. This incomplete frame provides extra traffic to the network.